I wouldn't be surprised after Windows 8.1 releases and people pick that up more. Some people wait until that OS's SP1 release for stability or to make sure the kinks are worked out. Hopefully, OEMs have their poop in a group for proper PCs for such.
Obviously there are workarounds, but it seems like you have settled for a workaround. I don't see any reason why if I am in the classic desktop and I fire up a PDF, that when I close the reader, I am NOT put back in the classic desktop where I came from but rather left on the new Start Screen. WTF.
Would you expect if you were on Windows 7, or Vista, or XP, or 2000, or 95 that if you launched an application (say Photoshop) that when you closed it, that Microsoft threw you into the start menu automatically. I sure wouldn't.
I'm surprised THAT many people are still using XP, not surprised at all that Windows 7 is still king.
Why would (or even should) you be surprised that people are still using XP. If it works and does what the user needs why should they bother to change.
I'm still driving a 13 year old 3 litre BMW -- still works really great (and it's a lot cheaper too since with that older engine I can run it using LPG (Liquid Petroleum Gas -- approx. mixture of propane and butane) . Where I am a litre of LPG is around 65% CHEAPER than a litre of Gas / Benzine / Petrol and its a lot cleaner too. Newer Diesel Engines aren't convertible so I even WIN by using an older car -- pay less tax too as emission is cleaner -- and if I used the ferry from Iceland ==>Scotland via Faroes Islands to take the car to the UK and was mad enough to even THINK of driving in Central London I wouldn't have to pay their "Congestion (??) Charge" either.
People don't always have to upgrade to "the latest and greatest" when there aren't any clear advantages in doing so. - Of course if you need to use newer hardware or apps and need better security then yes upgrade but for loads out there XP probably works just fine.
My Grandma taught me as a kid "Waste not .. Want not". I think this is still a great philosophy in our increasingly GREEDY commercial world where everybody is always talking about how they can "Monetise" their product.
Buy when YOU need -- not when some silly suited bozo tells you.